Assessing and Tax Data

Many communities have their assessor's databases online, including assessed value, recent sales history, tax burdens, and images. If you have to, for example, combat the latest urban legend about the Fleetwood Diner being sold for condos, here's where to start.

Trees

FallingFruit.org is a web application that uses Ann Arbor's tree data to show the location of approximately 17,000 trees planted by the city on curbsides and in parks. The information provided includes links to the USDA and Wikipedia for each species.

A variety of municipal and county data in KML format, as well as some PDF reports.

Public Mapping

MapWashtenaw, a joint venture between the Washtenaw County and the City of Ann Arbor provides a county-wide base map of roads and property parcels along with updated and historical aerial photography, topography accurate to within a few feet, and more.

Pipelines

Data about where gas, oil, and other petroleum products pipelines run is provided by PHMSA, the Pipeline and Hazardous Materials Safety Administration. The National Pipeline Mapping System allows you to view maps of where pipelines run, one county at a time.

U. S. Congress

OpenCongress.org - Top online resource for keeping tabs on legislation, lawmakers and the workings of Capitol Hill.

Related Information:

The organization Code for America who frequently hosts teams at National Day of Civic Hacking has a substantial number of projects in this space that can be forked, and many of those projects have created data standards that have since been leveraged in several communities. Rather than reinventing the wheel in the pursuit of a good idea, check both the list of projects and here for data standards to see if someone else has already done some of the heavy lifting.